Different Fish-Eating Habits and Cytokine Production in Chronic Urticaria with and without Sensitization against the Fish-Parasite Anisakis simplex

摘要

ABSTRACT Background Anisakis simplex sensitization has been associated with acute, but also with chronic urticaria. The objective of this study is to characterize chronic urticaria with (CU +) and without sensitization (CU-) against the ubiquitous fish parasite A. simplex in a transversal and longitudinal evaluation. Methods 16 CU + and 22 CU- patients were included and assessed for Urticaria activity score (UAS), fish-eating habits by standardized questionnaire and cytokine production (assessed by flow cytometric bead-based array) of peripheral blood mononuclear cells after stimulation with A. simplex extract or Concanavalin A (Con A). Patients were randomly put on a fish-free diet for three months and UAS, as well as cytokine production were again assessed. A difference of ≥ 1 in UAS was defined as improvement. Results There was no difference in UAS in both groups. Anisakis induced IL-2, IL-4 and IFN-γ production was higher in CU +. Con A induced IL-6 and IL-10 production was higher in CU +. CU + was associated with higher total fish intake, whereas CU- was associated with oily fish intake. The correlation of UAS was positive with oily fish, but negative with total fish intake. There was a better UAS-based prognosis in CU + without diet. Improvement was associated with higher Con A induced IL-10/IFN-γ as well as IL-10/IL-6 ratios. Further, previous higher oily fish intake was associated with improvement. Conclusions Our data confirm the different clinical and immunological phenotype of CU +. Our results show a complex relationship between fish-eating habits, cytokine production and prognosis, which could have important consequences in dietary advice in patients with CU. When encountering A. simplex sensitization, patients should not be automatically put on a diet without fish in order to reduce contact with A. simplex products.